Examples of various patent documents in the spinal implant area include the following:
U.S. Pat. No. 5,192,327 to Brantigan relates to a surgical prosthetic implant for vertebrae. More particularly, surgical prosthetic modular implants used singularly or stacked together are provided to support and fuse together adjacent vertebrae or to totally or partially replace one or more vertebrae in a vertebral column. The implants are rigid annular plugs, dimensionally similar to normal vertebral bodies, have simplified oval or hemi-oval shapes with ridged faces to engage adjacent vertebral bodies to resist displacement and allow bone ingrowth and fusion and to interdigitate with the ridges of an adjacent plug for modular stacking to allow variability of ultimate implant height. The implants can be provided in sets of different thicknesses and are internally grooved to receive an upstanding connecting bar to bind together the individual stacked implants into a stable unit. The annular implants have ample spaces to allow ingrowth of blood capillaries and packing of bone graft and are preferably made of a radiolucent material, preferably biocompatible carbon fiber reinforced polymers or are alternately made of traditional orthopaedic implant materials such as nickel, chromium, cobalt, stainless steel or titanium.
U.S. Pat. No. 5,397,364 to Kozak et al. relates to an anterior interbody fusion device. More particularly, an interbody fusion device includes a pair of lateral spacers and a pair of central spacers, each sized for percutaneous introduction through a disc resection portal in the disc annulus. Each of the lateral spacers includes opposing side faces defining a channel therein, while each of the central spacers includes arms at their opposite ends configured to be received within a channel of a corresponding lateral spacer. The arms and channels are interlocking to prevent separation of the components once assembled within the intradiscal space. The assembly of the central and lateral spacers defines a cavity therebetween for insertion of bone graft material. The central and lateral spacers are configured so that the bone graft cavity is oriented over the weakest, but most vascular and biologically active, bone of the vertebral body, while the lateral spacers are situated adjacent the disc annulus and over the strongest vertebral bone.
U.S. Pat. No. 6,159,211 to Boriani et al. relates to a stackable cage system for corpectomy/vertebrectomy. More particularly, surgical prosthetic modular devices used singularly or stacked together are provided for use to replace excised vertebral tissue. The devices are rigid plugs, dimensionally similar to normal vertebral bodies, and have ridged faces to engage adjacent vertebral bodies or to interdigitate when stacked. Ridges extend in both the medial/lateral and anterior/posterior directions to prevent slipping in the anterior/posterior and medial/lateral directions respectively. A locking screw may be used to secure a stack to form a singular rigid prosthetic device. The devices are also provided with a plurality of threaded openings. In the method of this invention, a device is used to replace excised vertebral tissue, threaded bolts are inserted into the threaded openings, and other spine stabilization devices are attached to the bolts. In corporectomies, the device can be bolted to a plate, which in turn is fixed to adjacent vertebrae. In spondylectomies, the device can be fixed to a series of posteriorly placed rods.
U.S. Pat. No. 6,468,311 to Boyd et al. relates to a modular interbody fusion implant. More particularly, an interbody fusion device for engagement between vertebrae includes a pair of lateral spacers for spacing the vertebrae, and a connecting member adapted to couple together the lateral spacers when inserted between the vertebrae. The connecting member, individual lateral spacers, or the entire spinal spacer can be made of bone in order to promote fusion of the vertebrae. The modular construction permits use of bone segments otherwise unsuitable due to size or strength in stable fusion devices.
U.S. Patent Application No. 2003/0040799 in the name of Boyd et al. relates to a modular interbody fusion implant. More particularly, an interbody fusion device for engagement between vertebrae includes a pair of lateral spacers for spacing the vertebrae, and a connecting member adapted to couple together the lateral spacers when inserted between the vertebrae. The connecting member, individual lateral spacers, or the entire spinal spacer can be made of bone in order to promote fusion of the vertebrae. The modular construction permits use of bone segments otherwise unsuitable due to size or strength in stable fusion devices.
Among those benefits and improvements that have been disclosed, other objects and advantages of this invention will become apparent from the following description taken in conjunction with the accompanying figures. The figures constitute a part of this specification and include illustrative embodiments of the present invention and illustrate various objects and features thereof.